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(#) `tools:viewBindingType` issues

!!! ERROR: `tools:viewBindingType` issues
   This is an error.

Id
:   `ViewBindingType`
Summary
:   `tools:viewBindingType` issues
Severity
:   Error
Category
:   Correctness
Platform
:   Android
Vendor
:   Android Open Source Project
Feedback
:   https://issuetracker.google.com/issues/new?component=192708
Since
:   7.1.0 (January 2022)
Affects
:   Resource files
Editing
:   This check runs on the fly in the IDE editor
Implementation
:   [Source Code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-checks/src/main/java/com/android/tools/lint/checks/ViewBindingTypeDetector.kt)
Tests
:   [Source Code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/ViewBindingTypeDetectorTest.kt)

All issues related to using the View Binding `tools:viewBindingType`
attribute.

(##) Example

Here is an example of lint warnings produced by this check:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text
res/layout/db.xml:5:Error: tools:viewBindingType is not applicable in
data binding layouts. [ViewBindingType]
    &lt;EditText android:id="@+id/test_view" tools:viewBindingType="TextView" /&gt;
                                          --------------------------------
res/layout/vb.xml:5:Error: tools:viewBindingType should be defined on a
tag that also defines an android:id. Otherwise, its value won't have any
effect. [ViewBindingType]
    &lt;EditText tools:viewBindingType="TextView" /&gt; &lt;!-- missing id --&gt;
              --------------------------------
res/layout/vb.xml:6:Error: tools:viewBindingType is not applicable on
<include> tags. [ViewBindingType]
    &lt;include android:id="@+id/included" layout="@layout/included" tools:viewBindingType="TextView" /&gt;
                                                                  --------------------------------
res/layout/vb.xml:7:Error: tools:viewBindingType is not defined
consistently, with the following types resolved across layouts:
android.view.SurfaceView, android.widget.TextView [ViewBindingType]
    &lt;EditText android:id="@+id/inconsistent" tools:viewBindingType="TextView" /&gt;
    ----------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Here are the relevant source files:

`res/layout/db.xml`:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers
&lt;layout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    tools:keep="@layout/db"&gt;
    &lt;EditText android:id="@+id/test_view" tools:viewBindingType="TextView" /&gt;
&lt;/layout&gt;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

`res/layout/vb.xml`:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers
&lt;LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    tools:keep="@layout/vb"&gt;
    &lt;EditText tools:viewBindingType="TextView" /&gt; &lt;!-- missing id --&gt;
    &lt;include android:id="@+id/included" layout="@layout/included" tools:viewBindingType="TextView" /&gt;
    &lt;EditText android:id="@+id/inconsistent" tools:viewBindingType="TextView" /&gt;
&lt;/LinearLayout&gt;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

`res/layout-land/vb.xml`:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers
&lt;LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    tools:keep="@layout/vb"&gt;
    &lt;SurfaceView android:id="@+id/inconsistent" /&gt;
&lt;/LinearLayout&gt;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

You can also visit the
[source code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/ViewBindingTypeDetectorTest.kt)
for the unit tests for this check to see additional scenarios.

(##) Suppressing

You can suppress false positives using one of the following mechanisms:

* Adding the suppression attribute `tools:ignore="ViewBindingType"` on
  the problematic XML element (or one of its enclosing elements). You
  may also need to add the following namespace declaration on the root
  element in the XML file if it's not already there:
  `xmlns:tools="http://schemas.android.com/tools"`.

* Using a special `lint.xml` file in the source tree which turns off
  the check in that folder and any sub folder. A simple file might look
  like this:
  ```xml
  &lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;lint&gt;
      &lt;issue id="ViewBindingType" severity="ignore" /&gt;
  &lt;/lint&gt;
  ```
  Instead of `ignore` you can also change the severity here, for
  example from `error` to `warning`. You can find additional
  documentation on how to filter issues by path, regular expression and
  so on
  [here](https://googlesamples.github.io/android-custom-lint-rules/usage/lintxml.md.html).

* In Gradle projects, using the DSL syntax to configure lint. For
  example, you can use something like
  ```gradle
  lintOptions {
      disable 'ViewBindingType'
  }
  ```
  In Android projects this should be nested inside an `android { }`
  block.

* For manual invocations of `lint`, using the `--ignore` flag:
  ```
  $ lint --ignore ViewBindingType ...`
  ```

* Last, but not least, using baselines, as discussed
  [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).

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